Laser anneal of buried metallic interconnects including through silicon vias

摘要

Disclosed is a process of annealing through silicon vias (TSVs) or other deeply buried metallic interconnects using a back side laser annealing process. The process provides several advantages including sufficient grain growth and strain relief of the metal such that subsequent thermal processes do not cause further grain growth; shorter anneal times thereby reducing cycle time of 3D device fabrication; and reduced pattern sensitivity of laser absorption.

主权项

1. A method comprising,
laser annealing a front side metallic interconnect from the back side of a structure comprising, from back to front, a transparent material substrate, an absorbing material region, and a semiconductor device region, wherein the metallic interconnect is located within the absorbing material region and semiconductor device region forming a vertical electrical connection (via), and wherein the laser annealing is conducted with a laser having a wavelength where the transparent material substrate does not substantially absorb the laser radiation and where the absorbing material region absorbs the laser radiation such that heat is generated and diffuses through the absorbing material.